target-arm: Improve semihosting debug prints

Print semihosting debugging information before the
do_arm_semihosting() call so that angel_SWIreason_ReportException,
which causes the function to not return, gets the same debug prints as
other semihosting calls. Also print out the semihosting call number.

Signed-off-by: Christopher Covington <christopher.covington@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Christopher Covington <cov@codeaurora.org>
Message-id: 1439483745-28752-3-git-send-email-peter.maydell@linaro.org

target-arm/helper.c

diff --git a/target-arm/helper.c b/target-arm/helper.c
index 7df1f06..114d56e 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -5228,8 +5228,10 @@
             nr = arm_lduw_code(env, env->regs[15], env->bswap_code) & 0xff;
             if (nr == 0xab) {
                 env->regs[15] += 2;
+                qemu_log_mask(CPU_LOG_INT,
+                              "...handling as semihosting call 0x%x\n",
+                              env->regs[0]);
                 env->regs[0] = do_arm_semihosting(env);
-                qemu_log_mask(CPU_LOG_INT, "...handled as semihosting call\n");
                 return;
             }
         }
@@ -5549,8 +5551,10 @@
             if (((mask == 0x123456 && !env->thumb)
                     || (mask == 0xab && env->thumb))
                   && (env->uncached_cpsr & CPSR_M) != ARM_CPU_MODE_USR) {
+                qemu_log_mask(CPU_LOG_INT,
+                              "...handling as semihosting call 0x%x\n",
+                              env->regs[0]);
                 env->regs[0] = do_arm_semihosting(env);
-                qemu_log_mask(CPU_LOG_INT, "...handled as semihosting call\n");
                 return;
             }
         }
@@ -5567,8 +5571,10 @@
             if (mask == 0xab
                   && (env->uncached_cpsr & CPSR_M) != ARM_CPU_MODE_USR) {
                 env->regs[15] += 2;
+                qemu_log_mask(CPU_LOG_INT,
+                              "...handling as semihosting call 0x%x\n",
+                              env->regs[0]);
                 env->regs[0] = do_arm_semihosting(env);
-                qemu_log_mask(CPU_LOG_INT, "...handled as semihosting call\n");
                 return;
             }
         }